The invention relates generally to a device and method for providing a specified volume of a medical fluid from a bulk source to a dose container.
Medical fluids are often packaged in standard size containers which are intended for single-use administration only. Typical containers include bags, bottles, vials, ampules, blister packs, etc. Once the factory seal on a medical fluid container is compromised, the Food and Drug Administration (FDA) mandates that the contents must be either administered within a set time interval or discarded. The underlying rationale for this regulation is that a medical fluid in an opened container has potentially been contaminated by either environmental pathogens or, if the container holds a multipatient fluid supply, by fluids from other patients. In multipatient or bulk fluid containers, the FDA has determined that if a continuous fluid path exists from the fluid to the patient, there is a possibility that the bulk fluid may be contaminated by exposure to a patient""s fluids. Even a separating unit that is inserted in the fluid path from a fluid source to a patient, for example, a drip chamber such as a conventional intravenous drip chamber, a mixing chamber, a filter, one or more check valves, a peristaltic pump, and/or other flow control devices, is considered insufficient as a barrier for purposes of sterility. A problem with these devices is that a continuous thin fluid film may exist across the valve seat and/or check mechanism, which provides a contamination pathway for blood and pathogens from the patient. Therefore, only a system having a physical separation between the fluid supply source and the patient will meet FDA standards. While the strictness of this requirement has increased costs to the hospital and patient because it limits the fluid in a bulk container to a single use, it has also desirably decreased the incidence of nosocomial infections in patients.
In current medical practice for fluid administration to a patient, medical personnel typically either use prefilled containers that hold a single patient (unipatient) supply of medical fluid, or they transfer a unipatient fluid supply to a container from a bulk source of the fluid. Use of prefilled containers adds to the cost of the fluid and/or the procedure in which the fluid is used, such as a contrast agent used to enhance an imaging procedure. Transfer of a unipatient supply of fluid to a container from a bulk source, while less expensive, adds an additional point of potential contamination. Typically, a clinician or technologist draws fluid into a unipatient container using a transfer tube or needle or, in some cases, pours the fluid into the container. Such transfers are best performed using aseptic techniques in an attempt to reduce exposure of the fluid to nonsterile air or other sources of contamination, although this is not always done in practice. These techniques reduce the likelihood of contamination, but sufficient risks still exist such that using any fluid remaining in the bulk supply source is not generally considered an acceptable medical practice. If anything less than the entire volume of fluid from the bulk supply source is transferred, the remaining fluid should be discarded, resulting in wasted material.
Many types of fluids are administered to patients, including diagnostic, therapeutic and physiologic fluids. These fluids are administered under a variety of circumstances and for a variety of reasons. For example, imaging procedures such as ultrasound, magnetic resonance imaging (MRI), angiography and computed tomography frequently require image enhancement by contrast agents. Contrast agents are fluids that are normally administered intravascularly to provide a better view of the organ or system to be imaged. The dose of contrast agent is determined to achieve optimal imaging without providing excess agent, since the agent may be expensive and/or difficult to be efficiently removed from the body. The maximum dose is based upon pharmacokinetic limits, specified as milligrams (mg) of active ingredient per kilogram (kg) of patient body weight, and the minimum dose is predicated on achieving clinically viable diagnostic information from the imaging procedure. The range between the minimum dose and maximum dose varies widely for any given imaging procedure and patient. The optimal dose is influenced by a number of parameters, such as the image equipment technology, diagnostic techniques, clinician experience, and patient-specific parameters such as age, presence of pathology, physical proportions and other physiological parameters. For a xe2x80x9ctypicalxe2x80x9d 70 kg male patient in good health, a volume of about 100 ml of contrast agent is normally administered.
Use of fluid from a bulk source would facilitate timely administration of such fluids. For example, in imaging procedures it is common for physicians to administer excess x-ray contrast agent. Since higher blood concentrations of contrast agent generally yield improved images, physicians often reason that the excess volume is justified because it decreases the probability that a repeated image will be needed. Accordingly, there are now standardized protocols in which the maximum volume of x-ray contrast agent is used. The maximum volume is often based upon the available standard packaging sizes and concentrations from the manufacturers of contrast agents, and the entire content of the package is typically utilized regardless of its clinical necessity. This practice results in over medication and commensurate safety concerns for the patient, since adequate diagnostic information may be obtained at a dose that is well below even the maximum physiological threshold for a particular patient. Administration of excess agent may have nominal to severe pharmacological consequences, depending upon the condition of the patient and the identity of the agent.
Administration of less than the optimal volume of contrast agent may also have consequences, determined by the particular circumstances. For example, an optimal volume of agent may be required to be administered within a predetermined period of time. If the time of administration exceeds the predetermined time, the result may suboptimal imaging. Administration of a suboptimal volume may require performing the entire procedure at a later time and/or administering a second dose of agent. Suboptimal dosing thus exposes the patient to the possibility of receiving two doses of the agent in a short period of time, potentially compromising patient health and well being, and is a time- and cost-inefficient process.
A system is thus needed to provide a desired volume of a medical fluid from a bulk source in a medically acceptable, cost- and time-efficient manner.
The invention is directed to a medical fluid delivery system. The system comprises a bulk container for containing a bulk or multipatient fluid supply, a connecting site for access to the fluid in the bulk container, and a dose container for receiving a unipatient supply of fluid from the bulk container at the connecting site. The system may have a device to maintain sterility of the connecting site. The dose container may also function as a delivery container with either inflexible walls, e.g., a syringe, or at least one flexible wall, e.g., a bag. The system may contain a detector for the presence of air and may be automated.
The invention is also directed to a method of delivering a medical fluid. A bulk container for containing a multipatient fluid supply, a connecting site for access to the fluid supply in the bulk container, and a delivery container for receiving a unipatient supply of fluid from the bulk container at the connecting site and for delivering the fluid supply to a patient, is provided. A fluid flow is established from the bulk container to the delivery container at the connecting site to fill the delivery container. The delivery container is irreversibly disconnected from the bulk container at the connecting site and the fluid supply is thereafter delivered to the patient. The delivery container may have at least one flexible wall that contacts a pressurizeable chamber, with the unipatient fluid supply delivered to the patient from the delivery container by providing pressure to the flexible wall of the delivery container. The unipatient fluid supply may be a dose that has been customized for the patient by, for example, using an algorithm for patient and/or procedure specific data.
The invention is further directed to a method of maintaining sterility of a medical fluid that is dispensed from a bulk container to a dose and/or delivery container at a connecting site by providing a sterile environment at the connecting site. The connecting site may be enclosed in a controlled-access device with a filtered air flow adjacent the connecting site, or may be irradiated or provided with a chemical sterilant.
The invention is also directed to a sterile connector to access fluid in a bulk container. The connector has a first compartment to enclose a site to access fluid flow from a bulk container and a device to engage the access site to provide fluid flow to a connecting site in a second compartment. The connector also has the aforementioned second compartment for the connecting site and with a receiving projection and a conduit for providing a sterilant to the connecting site. The connector has a fluid evacuating channel which transverses the interior of the engaging and receiving projections, through which fluid from the bulk container is supplied to the receiving projection, and a channel for atmospheric pressure access which transverses the interior of the engaging projection and through which a filtered access to normal atmosphere is supplied to the bulk container. The second compartment terminates in a device to control access to the receiving projection. The controlled access device may be a door extending from the end of second enclosure, opening inwardly to expose the receiving projection and closing when not engaged.
The invention is still further directed to a medical fluid delivery system comprising a bulk container for containing a multipatient fluid supply and having a connector for providing a unipatient fluid supply to fill a flexible wall delivery container. The flexible wall container is connected to the system at the connecting site, either directly or indirectly, for filling with the unipatient fluid supply. After filling, the flexible wall container is irreversibly disconnected from the system at the connecting site and may then connect to a patient connector.
The invention is also directed to a medical fluid delivery system comprising a bulk container containing a multipatient fluid supply, having a connector for providing a unipatient fluid supply to a syringe at a connecting site and thereafter irreversibly disconnecting at the connecting site. The syringe may connect to a patient connector after disconnecting at the connecting site. The syringe may comprise a barrel for containing a unipatient fluid supply, a filling port that is operatively attached to the barrel and having a tube and a check valve, a discharge port, and a piston for discharging the fluid through the discharge port.
The invention is additionally directed to a method for providing a customized supply of a medical fluid to a patient. The customized supply is determined, then a bulk container containing a multipatient supply of the fluid and having a connecting site to access the fluid is provided and a delivery container for receiving the customized supply from the bulk container at the connecting site and for delivering the customized supply to the patient is also provided. A fluid flow from the bulk container to the delivery container is established by connecting the delivery container to the bulk container at the connecting site to provide the customized supply to the delivery container. The delivery container is irreversibly disconnected from the bulk container at the connecting site and thereafter the customized supply is delivered to the patient. In one embodiment, the system is automated.
The invention is also directed to a medical fluid delivery system providing at least one bulk container having at least a first port for attaching a first connector from the bulk container to a connecting site, and a unipatient supply container having at least a second port for receiving a unipatient supply of fluid at the connecting site and thereafter disconnecting at the connecting site. The system may further include a plurality of connectors, such as a second connector between the connecting site and the delivery container, a third connector to deliver the unipatient supply from the delivery container to a patient, etc.
The invention also includes a medical fluid delivery system in which the delivery container has at least one flexible wall and the fluid is delivered to a patient by providing a pressure to a pressurizeable chamber adjacent the flexible wall of the delivery container. The pressure may be hydraulic, mechanical, and/or pneumatic. The delivery container may be prefilled with the fluid, or may be filled using the system of the invention with fluid from a bulk container containing a multipatient supply of the fluid and having a connector to the delivery container.
The invention substantially reduces cross contamination from a bulk source to a patient, and from one patient to another patient receiving fluid from the same bulk source. The dose and/or delivery container is completely and irreversibly disconnected from a bulk container before connecting to a patient. Thus, there is no continuous fluid path from the bulk container to a patient. In one embodiment, the invention automatically fills and injects a predetermined volume of fluid that has been customized for a particular patient, resulting in cost and time efficiency and enhanced patient safety. The invention facilitates the safe administration of a medical fluid from a bulk container while minimizing waste of the fluid and pharmacological hazards due to insufficient or excess administration. Any type of fluid or combinations of fluids may be administered in the method of the invention, such as diagnostic fluids, therapeutic fluids, physiologic fluids, etc.
The objectives and other advantages of this invention will be further understood with reference to the following detailed description and examples.